Pro: Medial UKA- The Robot gets it Perfect David J. Mayman, MD - - PowerPoint PPT Presentation

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Pro: Medial UKA- The Robot gets it Perfect

David J. Mayman, MD

Assoc iate Pr

• fe ssor

Or thopae dic Sur ge r y Hospital for Spe c ial Sur ge r y

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Disclosure

Consultant: Smith and Nephew Stock Options: OrthAlign Stock Options: Imagen

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Unicondylar Knee Arthroplasty

Why UKA??

• KNEE CONSERVATION!!

– Preserve ACL/PCL – Low complication rate1 – Rapid return to work – Possible cost saving

• RETURN TO SPORT!!

– 96% of pts return to preop level of sports2 – 90% maintained or improved sports activities3

1Brown et al J Arthroplasty 2012 2Hopper et al KSSTA 2008

3Naal et al AJSM 2007

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

The Problem with UKA Durability Concerns

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

The Problem with UKA Durability Concerns

• Higher Revision Rate than TKR??

– 98% 10 yr survivorship (Miller-Galante)

• Berger CORR 1999

– 98% 11 yr survivorship in young patients

• Pennington JBJS 2003

– 98% 10 yr survivorship (Oxford)

• Murray JBJS Br 1998

– 84% 22 year survivoship (Marmor)

• Squire CORR 1999

Te Technically c nically challe lleng nging! ing!!

Low Low vol

• lum

ume e sur urgeons geons hav have e 6-8x 8x hi high gher er rev evision

• n rat

ate e

Tr Tregon

• nning J

JBJS Br 2009 09

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Rationale for Robotics in UKA Failure often Associated w/ Technical Error

• Surgical technique has dominant effect on
• utcome

– Lower limb alignment

• avoid over and undercorrection

» Hernigou CORR 2004

– Varus angulation of tibial slope

• attempt to reduce

» Engh J Arthroplasty 2006

– Posterior slope of implant

• avoid slope >7 deg

» Hernigou JBJS 2004

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Rationale for Robotics in UKA

• CAS techniques can improve positioning

reliability in UKA

• Keene JBJS Br 2006

– 20 navigated vs 20 conventional UKA; endpoint ± 2° of the pre-operative plan » Navigated UKR – 17/20 (87%) » Conventional UKR – 12/20 (60%)

• Cobb JBJS Br 2006

– Prospective, randomized trial – Oxford Uni robot (n=13) vs conventional (n=14) – Robot » 100% coronal plane alignment within 2°

• f CT plan

– Conventional

» 40% within 2° of CT plan – Trend toward improved WOMAC with robotics at 6 wks and 3 mos

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Computer Assisted Surgery - The Big Idea

Enhance Control of Surgical Variables to Improve Outcomes

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Variables that Influence Outcome of UKA

• Implant positioning
• Patient selection
• Fixation
• Lower Limb Alignment
• Proper sizing
• Implant design

– Inlay – Onlay – Mobile bearing

• Soft tissue balance

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Variables that Influence Outcome of UKA

• Variables Controlled by

Robotic Tool

– Implant Positioning – Soft-Tissue Balance – Lower Limb Alignment – Proper Sizing

• Variables Independent of

Robotic Tool

– Fixation – Implant Design – Patient selection

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Robotic UKA

• Implant Pre-Planning (CT based

Analysis)

– Sizing – Implant positioning

• Registration (Robot and Patient

Anatomy)

• Gap Planning (Virtual Trialing)

– Soft tissue balance – Long leg alignment

• Robotic Execution of Plan
• Removal of osteophytes and

meniscus

• Implant position verification

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Technical Question

Do We Control Surgical Variables with Robot??

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Variable – Implant Position

Accuracy Study – Manual I nstruments vs. Robotic Guidance Citak et al Knee 2012 Manual Robotic Instruments Guidance

2 4 6 8 10 Position Orientation Position Orientation RMS Error (mm or deg)

Femur Tibia

Manua l

• Femoral component RMS placement

errors 3x more accurate (p<0.05) and 3.1x less variable (p<0.05)

• Tibial component RMS placement errors

3.4x more accurate (p<0.05) and 2.6x less variable (p<0.05)

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

The Big Question

Does Control of these Variables Impact Clinical Outcome??

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Tw Two

• Year

ear S Sur urvivor

• rshi

hip of p of R Robot

• botical

ally Assisted ed UKA: A Mul ulticen enter er S Study udy

Pea earle A AD, C Carr arroll K KM, M, Van an D Der Li er List J J, Coo

• on T, Doun

unchis his JS, JS, Boru rus T, T, Buec eche hel F, Roche M he M

• 1008 eligible patients (1136 knees) identified – first series of MCK

Medial Onlay UKA from 6 surgeons from implant release date (consecutive for each surgeon)

– 35 patients declined to participate – 15 patient deceased – 160 patients lost to follow up

• 797 patients (909 knees) enrolled in study and contacted

– 78% follow up rate – 56% Male, 44% Female – 112 (14%) Bilateral UKA – Average age: 69 ± 9.5 years – Average BMI: 29.4 ± 4.9

• Lowest volume surgeon: 4.6 procedures per month
• Highest volume surgeon: 15.8 procedures per month

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Res esults ults - Surv urviv ivor

• rship

ship 98. 98.8% 8% surv urvivorship at t vorship at two y

• years

ears

Swedis edish R h Regis egistry 2 2 year year revi revision

• n rat

rate: 4. 4.5% 5% Aust ustra ralian an R Regis egistry 2 2 year year revision ision

The annual revision rate was 0.49 revisions per year

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Resu sults lts - Sa Satis isfac action

• n
• 92%

2% p pat atient nts “ “Very S Sat atisfied” or

• r “Sat

atisfied”

• 75% of

75% of TKA pat patien ents “ s “Ver ery S y Sat atisf sfied” or

• r “Sat

atisf sfied ed” ( (Nobl

• ble et

e et al al.) – 1 i 1 in 5 n 5 TKA patients “Dissatisfied” with outcome (Bourne et al.)

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

No difference between centers (p=0.559)

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Literature Survivorship at 2 years

Table 3. Studies and annual registries that published two year survivorship of UKA

Author/Country Year Published Start Cohort End Cohort UKA (n) Survivorship at two- year follow-up Cohort Studies Bonutti et al.39 2011 2000 2007 80 93.0 % Eickmann et al.36 2006 1984 1998 411 96.0 % Hamilton et al.37 2014 2001 2004 517 97.0 % Liebs et al.38 2013 2002 2009 401 94.7 % Lim et al.40 2012 2001 2011 400 97.4 % Pandit et al.17 2011 1998 2009 1000 98.0 % Vorlat et al.41 2006 1988 1996 149 97.8 % Yoshida et al.16 2013 2002 2011 1279 98.3 % Annual Registries Australia11 * 2014 1999 2013 41250 97.8 % New Zealand12 * 2013 2000 2012 7388 98.1 % Sweden4* 2013 1999 2012 95.3 % United Kingdom42 2013 2003 2010 30795 95.6 % Cohort Studies 96.5 % Annual Registries 96.7 % UKA indicates unicompartmental knee arthroplasty.

* These registries reported combined medial and lateral UKA survivorship with predominantly medial

UKA

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Summary

• Robotic UKR allows for:
• Customized control of implant positioning
• Reliable lower limb realignment
• Control of soft tissue balance
• Back to work in 2 weeks
• Return to sports

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Added Stress?

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Added Stress?

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Reaction to Robotics

Initially… Now…..

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Is it JUST Marketing???

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Same Surgeon, Same Day

ADULT RECONSTRUCTION AND JOINT REPLACEMENT

Thank you